US5456986A - Magnetic metal or metal carbide nanoparticles and a process for forming same - Google Patents

Magnetic metal or metal carbide nanoparticles and a process for forming same Download PDF

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US5456986A
US5456986A US08/085,298 US8529893A US5456986A US 5456986 A US5456986 A US 5456986A US 8529893 A US8529893 A US 8529893A US 5456986 A US5456986 A US 5456986A
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Sara Majetich
Michael McHenry
Joseph Artman
Stuart Staley
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Carnegie Mellon University
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    • B22F9/00Making metallic powder or suspensions thereof
    • B22F9/16Making metallic powder or suspensions thereof using chemical processes
    • B22F9/18Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
    • B22F9/20Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds
    • BPERFORMING OPERATIONS; TRANSPORTING
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    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER
    • B22F1/00Special treatment of metallic powder, e.g. to facilitate working, to improve properties; Metallic powders per se, e.g. mixtures of particles of different composition
    • B22F1/0003Metallic powders per se; Mixtures of metallic powders; Metallic powders mixed with a lubricating or binding agent
    • B22F1/0007Metallic powder characterised by its shape or structure, e.g. fibre structure
    • B22F1/0011Metallic powder characterised by size or surface area only
    • B22F1/0018Nanometer sized particles
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    • B22F1/02Special treatment of metallic powder, e.g. to facilitate working, to improve properties; Metallic powders per se, e.g. mixtures of particles of different composition comprising coating of the powder
    • BPERFORMING OPERATIONS; TRANSPORTING
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    • B22F9/14Making metallic powder or suspensions thereof using physical processes using electric discharge
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y25/00Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
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    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00Carbon; Compounds thereof
    • C01B32/90Carbides
    • C01B32/907Oxycarbides; Sulfocarbides; Mixture of carbides
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/0036Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties showing low dimensional magnetism, i.e. spin rearrangements due to a restriction of dimensions, e.g. showing giant magnetoresistivity
    • H01F1/0045Zero dimensional, e.g. nanoparticles, soft nanoparticles for medical/biological use
    • H01F1/0054Coated nanoparticles, e.g. nanoparticles coated with organic surfactant
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    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER
    • B22F2999/00Aspects linked to processes or compositions used in powder metallurgy
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    • C01P2004/64Nanometer sized, i.e. from 1-100 nanometer
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    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C26/00Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
    • C22C2026/001Fullerenes
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00Nanotechnology
    • Y10S977/70Nanostructure
    • Y10S977/734Fullerenes, i.e. graphene-based structures, such as nanohorns, nanococoons, nanoscrolls or fullerene-like structures, e.g. WS2 or MoS2 chalcogenide nanotubes, planar C3N4, etc.
    • Y10S977/742Carbon nanotubes, CNTs
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S977/00Nanotechnology
    • Y10S977/70Nanostructure
    • Y10S977/832Nanostructure having specified property, e.g. lattice-constant, thermal expansion coefficient
    • Y10S977/838Magnetic property of nanomaterial
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/29Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991Coated
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/29Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991Coated
    • Y10T428/2993Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/30Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A magnetic metal or metal carbide nanoparticle is provided having a carbon coating. The nanoparticle has a diameter in the range of approximately 5 to 60 nm, and may be crystalline or amorphous. The magnetic metal or metal carbide nanoparticle is formed by preparing graphite rods which are packed with a magnetic metal oxide. The packed graphite rods are subjected to a carbon arc discharge to produce soot containing magnetic metal or metal carbide nanoparticles and non-magnetic species. The soot is subsequently subjected to a magnetic field gradient to separate the magnetic metal or metal carbide nanoparticles from the non-magnetic species. Ferromagnetic or paramagnetic compounds are made by starting with graphite rods packed with the oxides of iron, cobalt, nickel and manganese bismuth, or a rare earth element excluding lanthanum, lutetium and promethium, or a paramagnetic transition metal.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of magnetic metal or metal carbide compounds and carbon-coated magnetic metal or metal carbide compounds. Particularly, the present invention relates to the field of carbon-coated magnetic metal or metal carbide nanoparticles and the methods for preparing the same. Nanoparticles include crystalline or amorphous particles 5 to 60 nanometers in diameter and nanotubes up to 1 centimeter long and 5 to 60 nanometers in diameter.

2. Description of the Prior Art

Small magnetic particles have many applications. Such particles are used as toner in xerography, in ferrofluid vacuum seals, in nuclear magnetic resonance imaging as contrast agents, and in magnetic data storage. These magnetic particles are typically micron-sized in diameter or larger. The large size of these particles renders them less than satisfactory for several specialized applications.

If the magnetic particles were smaller, better resolution would be achieved in xerographic applications. In ferrofluid applications, the enhanced solubility due to carbon coating provided by smaller particles may be advantageous. In magnetic data storage, resolution may be enhanced by using smaller particles. Consequently, there is a potential need for sub-micron sized magnetic metal carbon-coated particles and a method for producing bulk amounts of these particles in a high yield process.

Recently, there has been increased investigation regarding the Kratschmer-Huffman carbon arc method of preparing fullerenes, or small hollow carbon clusters. These fullerenes are typically in the order of 1 nm in diameter. Recently, it has further been discovered that these hollow carbon clusters can be filled with metal ions. This can be accomplished by drilling out the graphite rods and packing them with a mixture of metal oxide powder and graphite cement before generating the soot by the carbon arc. Rodney S. Ruoff, Donald C. Lorents, Bryan Chan, Ripudaman Malhotra, and Shekhar Subramoney, Science, Vol. 259, p. 346 (1993) discussed the production of 20-40 nm diameter carbon-coated lanthanum carbide nanocrystallites by this method. Similar results were reported by Masato Tomita, Yahachi Saito and Takayoshi Hayashi in Jpn. J.Appl. Phys., Vol. 32, p. 280 (1993).

The carbon arc method of preparing lanthanum carbide nanocrystallites discussed above generates fullerenes and graphitic soot in addition to the ianthanum carbide nanocrystailites. In order Lo be useful, a means of separating the nanocrystallites is essential. So far, no chemical methods have been found to be successful in separating macroscopic amounts of nanoparticles from graphitic soot and fullerenes. Such separation processes are rendered extremely important when the yields achieved for the nanoparticles is in the order of ten percent or less of the soot. Accordingly, there is a need for a method to separate carbon-coated metal nanoparticles from graphitic soot.

SUMMARY OF THE INVENTION

By using a modification of the Kratschmer-Huffman carbon arc method, carbon coated nanoparticles having a diameter in the range of approximately 5 to 60 nm can be formed. If a paramagnetic rare earth metal oxide or the oxide of a ferromagnetic species is packed into a graphite rod and subsequently subjected to a carbon arc discharge, soot containing magnetic metal or metal carbide nanoparticles and non-magnetic species is formed. The magnetic metal or metal carbide nanoparticles can be separated from the soot by subjecting the soot to a magnetic field gradient.

In the magnetic separation step, the nanoparticle-containing soot is ground to a fine powder and then dropped down an electrically grounded metal tube through a magnetic field gradient created by a pair of strong magnets. Non-magnetic material passes through the tube, but magnetic components are suspended if the field gradient force exceeds the gravitational force. When the apparatus is moved away from the magnets, the magnetic material is released into its own separate collection container. This process can be used to separate paramagnetic or ferromagnetic species from non-magnetic components of the soot produced by the carbon arc discharge process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a transmission electron micrograph of a carbon-coated gadolinium carbide nanocrystallite formed in accordance with the present invention.

FIG. 2 is an electron diffraction pattern of a gadolinium carbide nanocrystallite formed in accordance with the present invention.

FIG. 3 is a SQUID magnetometer measurement of M(H,T) for a 10 mg nanocrystalline gadolinium carbide specimen separated in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A process based on the Kratschmer-Huffman carbon arc method of preparing fullerenes can be used to generate carbon-coated magnetic metal or metal carbide nanoparticles. When combined with a magnetic field gradient separation technique, bulk amounts of these nanoparticles can be isolated.

If graphite rods which are packed with a paramagnetic rare earth metal oxide or the oxide of a ferromagnetic material are subsequently subjected to a carbon arc discharge, the soot produced by the Kratschmer-Huffman carbon arc process contains magnetic metal or metal carbide nanoparticles and non-magnetic species.

A magnetic field gradient can be used to separate the magnetic metal or metal carbide nanoparticles from the non-magnetic species included in the soot. Preferably, the soot produced by the carbon arc discharge method is further ground to a fine powder before being subjected to the magnetic field gradient. If the magnetic field gradient force is greater than the gravitational force, the magnetic nanoparticles will be suspended by the magnets in the separator tube whereas the non-magnetic species will pass through. This magnetic gradient separation technique removes non-magnetic byproducts of the carbon arc discharge process and enhances the magnetic response of the isolated material. This separation process separates all paramagnetic or ferromagnetic components from the remaining soot.

FIG. 1 is a transmission electron micrograph of a gadolinium carbide nanocrystallite, enclosed by several curved graphitic sheets, which was formed in accordance with the present invention. In order to form the gadolinium carbide nanocrystallite shown in FIG. 1, 1/4 inch diameter graphite rods were drilled and packed with a mixture of metal oxide powder, in this case Gd2 O3, and a combination of graphite powder and graphite cement. A 1:1 volume ratio of Gd2 O3 and graphite powder bound together with a minimum amount of graphite cement was used. The rods were baked overnight at 300° C. to drive off water vapor. These graphite rods were then used in the upper electrode position in an AC carbon arc. The arc conditions were 100 A and 25 V, and a helium gas pressure of 125 Tort was applied. A DC carbon arc with the same conditions and the filled graphite rod as the positive electrode also yields these nanocrystallites.

The carbon arc discharge process described above produced a soot which included a mixture of graphitic particles, carbon-coated gadolinium carbide nanoparticles and fullerenes. This raw soot was magnetically separated by first grinding it to a fine, micron-sized powder with a mortar and pestle. This ground soot was then passed through a magnetic field gradient to separate the magnetic from the non-magnetic species. In this example, the separator consisted of a funnel, an electrically-grounded aluminum tube with a pair of 1"×1"×1/2" neodymium iron boron magnets on either side, and a pair of collection flasks. The grounded metal tube prevents electrostatic charging of the powder.

In the separator tube, a paramagnetic particle experiences a gravitational force in addition to a magnetic force proportional to the field gradient, the field H, and the susceptibility χ given by the following formula:

F.sub.M =χ(H·∇)H

In the separator tube, a ferromagnetic particle with a moment M experiences a magnetic force given by the following equation:

F.sub.M =(M·∇)H

The aluminum tube was positioned appropriately between the magnets in order to maximize the magnetic force, FM. When small amounts of powder were poured through the apparatus, the magnetic species were suspended by the magnets, while the non-magnetic fraction passed through. The collection bottles were switched, and the tube was moved away from the magnets to release the magnetic powder. After the first pass, roughly 1/8th of the original volume was found to be magnetic for the case of gadolinium. For cobalt, 95% of the soot produced was found to be magnetic after the first pass. This powder was passed through repeatedly to enhance the abundance of magnetic material. The final magnetic "filtrate" contained a mixture of magnetic nanocrystallites embedded in a carbon matrix, and possibly small amounts of endohedral fullerenes. The fullerenes were removed by extraction in carbon disulfide. No visible differences were observed between pure carbon soot and the gadolinium-containing mixture. Hence, separation of the gadolinium-containing compounds would have been difficult, if not impossible, without the magnetic separation technique.

The structural properties of the magnetic powder were examined by electron microscopy. Energy dispersive spectroscopy indicated that the gadolinium was uniformly distributed in the magnetic soot. Closer inspection was made with a JEOL 4000 400 key high resolution transmission electron microscope. Samples were prepared by dispersing the powder in methanol with the aid of ultrasound and drying a drop of the solution on an amorphous carbon-coated copper grid. A gadolinium carbide nanocrystallite encased in curved graphitic shells as shown in FIG. 1, along with smaller crystallites enclosed in amorphous carbon, were observed. In some of the larger nanocrystallites with a diameter approximately 50 nm, up to 30 graphitic layers were seen, and some of the particles were faceted.

X-ray diffraction of the nanocrystallites with a Rigaku diffractometer revealed sharp peaks indicating the presence of a single Gd2 C3 phase, along with the graphitic peaks and a broadened peak at small angles characteristic of the fullerenes. Comparison with tabulated crystal structures suggest that the most abundant phase is paramagnetic body-centered cubic Gd2 C3. This structural assignment is on the Oasis of both x-ray diffraction peaks and on electron diffraction of a crystalline oriented in the [110] direction as shown in FIG. 2. No evidence was seen for α-GdC2, Gd2 C, or Gd2 O3 phases, or for Gd crystallites. This is different from the case of lanthanum doping, for which α-LaC2 nanocrystallites were observed.

Room temperature electron paramagnetic resonance spectra of the powder at 9.104 GHz showed a single broad derivative centered at 3130 G, corresponding to a g-value of 2.08. This is consistent with the g-value predicted for a J=S=7/2 ground state for a Gd+3 ion.

Magnetization data were obtained for powder samples using a Quantum Design SQUID Magnetometer. M(H,T) has been determined in solenoidal fields between ±5 T and for temperatures from 4° to 300° K. FIG. 3 shows magnetization data for different temperatures scaled as a function of H/T. The data fall on a paramagnetic response curve. Fits of this data taken at several temperatures allow assignment of a J=7/2 ground state consistent with the EPR results. Ferromagnetic behavior was observed in similar cobalt nanocrystallites.

The encapsulation method, in combination with the magnetic separation technique, has been used to prepare ferromagnetic transition metal complexes containing iron, cobalt, nickel and manganese bismuth, and paramagnetic rare earth metal complexes containing gadolinium and holmium. The encapsulation method can form additional paramagnetic complexes using the rare earth metals except lanthanum, lutetium and promethium. The phases produced appear to be specific to the metal used. However, the production and separation processes are generally applicable to all magnetic species.

In a refinement of the present process, increasing the magnetic separator field of the separation has been found to differentiate among the various magnetic nanoparticles. By varying the field, magnetic nanoparticles having different magnetic moments per volume may be segregated. Such a process can be used to further separate the magnetic nanoparticles to isolate those having desired properties.

It has been discovered that if the helium pressure is increased during the carbon arc discharge process, the carboncoated magnetic particles are formed in the shape of nanotubes instead of nanocrystallites. The application of such nanotubes in composite materials may provide certain advantages. In another modification of the present invention, it has been discovered that amorphous magnetic nanoparticles can be formed by packing the graphite rods with appropriate mixtures of two oxide powders.

In the foregoing specification certain preferred practices and embodiments of this invention have been set out, however, it will be understood that the invention may be otherwise embodied within the scope of the following claims.

Claims (10)

We claim:
1. A magnetic metal or magnetic metal carbide nanoparticle having a coating consisting essentially of elemental carbon, said nanoparticle having a diameter in the range of approximately 5 to 60 nm.
2. The nanoparticle of claim 1 wherein said nanoparticle is one of a crystallite having a diameter in the range of approximately 5 to 60 nm, an amorphous particle having a diameter in the range of approximately 5 to 60 nm or a nanotube having a length less than 1 cm and having a diameter in the range of 5 to 60 nm.
3. The nanoparticle of claim 1 wherein said nanoparticle is one of a paramagnetic or ferromagnetic compound.
4. The nanoparticle of claim 3 wherein said ferromagnetic compound is selected from the group consisting of iron, cobalt, nickel, and manganese bismuth.
5. The nanoparticle of claim 3 wherein said paramagnetic compound is selected from the group consisting of the rare earth metals except for lanthanum, lutetium and promethium.
6. A magnetic metal or magnetic metal carbide nanoparticle formed by preparing graphite rods, said graphite rods being packed with a magnetic metal oxide, subjecting said packed graphite rods to a carbon arc discharge to produce soot containing magnetic metal or magnetic metal carbide nanoparticles and non-magnetic species, and applying a magnetic field gradient to said soot to separate said magnetic metal or magnetic metal carbide nanoparticles from said non-magnetic species.
7. The nanoparticle of claim 6 wherein said nanoparticle is one of a paramagnetic or ferromagnetic compound.
8. The nanoparticle of claim 7 wherein said ferromagnetic compound is selected from the group consisting of iron, cobalt, nickel, and manganese bismuth.
9. The nanoparticle of claim 7 wherein said paramagnetic compound is selected from the group consisting of the rare earth metals except for lanthanum, lutetium and promethium.
10. The nanoparticle of claim 7 wherein said nanoparticle is segregated by magnetic moment per volume by varying the magnetic field gradient applied to said soot.
US08/085,298 1993-06-30 1993-06-30 Magnetic metal or metal carbide nanoparticles and a process for forming same Expired - Lifetime US5456986A (en)

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US08/085,298 US5456986A (en) 1993-06-30 1993-06-30 Magnetic metal or metal carbide nanoparticles and a process for forming same
US08/265,008 US5549973A (en) 1993-06-30 1994-06-24 Metal, alloy, or metal carbide nanoparticles and a process for forming same
KR1019950706048A KR960703487A (en) 1993-06-30 1994-06-29 Metal, alloy, or metal carbide particles and a method of forming electrode (metal, alloy, or metal carbide nanoparticles and a process for forming same)
JP7503688A JPH09506210A (en) 1993-06-30 1994-06-29 Metal, alloy or metal carbide nano level fine particles and manufacturing method thereof
PCT/US1994/007601 WO1995001643A1 (en) 1993-06-30 1994-06-29 Metal, alloy, or metal carbide nanoparticles and a process for forming same
CN94192652A CN1064777C (en) 1993-06-30 1994-06-29 Metal, alloy, or metal carbide nanoparticles and process for forming same
EP94921485A EP0706709A1 (en) 1993-06-30 1994-06-29 Metal, alloy, or metal carbide nanoparticles and a process for forming same
US08/658,788 US5783263A (en) 1993-06-30 1996-06-05 Process for forming nanoparticles

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Cited By (58)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5627140A (en) * 1995-05-19 1997-05-06 Nec Research Institute, Inc. Enhanced flux pinning in superconductors by embedding carbon nanotubes with BSCCO materials
WO1997019208A1 (en) * 1995-11-22 1997-05-29 Northwestern University Method of encapsulating a material in a carbon nanotube
US5660397A (en) * 1994-09-23 1997-08-26 Holtkamp; William H. Devices employing a liquid-free medium
US5766306A (en) * 1996-06-04 1998-06-16 The Boeing Company Continuous process for making nanoscale amorphous magnetic metals
US5783263A (en) * 1993-06-30 1998-07-21 Carnegie Mellon University Process for forming nanoparticles
US5834057A (en) * 1996-06-28 1998-11-10 The United States Is Represented By The Secretary Of The Navy Method of making chemically engineered metastable alloys and multiple components nanoparticles
US5984996A (en) * 1995-02-15 1999-11-16 The University Of Connecticut Nanostructured metals, metal carbides, and metal alloys
US6033624A (en) * 1995-02-15 2000-03-07 The University Of Conneticut Methods for the manufacturing of nanostructured metals, metal carbides, and metal alloys
US6231980B1 (en) * 1995-02-14 2001-05-15 The Regents Of The University Of California BX CY NZ nanotubes and nanoparticles
US6290735B1 (en) * 1997-10-31 2001-09-18 Nanogram Corporation Abrasive particles for surface polishing
US6340245B1 (en) * 1997-09-16 2002-01-22 Skf Engineering & Research Centre B.V. Coated rolling element bearing
US6376063B1 (en) 1998-06-15 2002-04-23 The Boeing Company Making particulates of controlled dimensions by electroplating
DE10111321A1 (en) * 2000-09-08 2002-05-23 Nanosolutions Gmbh Production of inorganic nanoparticles that can be fluoresced comprising host material containing dopant comprises using organic solvent for liquid phase synthesis of particles
US6479028B1 (en) 2000-04-03 2002-11-12 The Regents Of The University Of California Rapid synthesis of carbon nanotubes and carbon encapsulated metal nanoparticles by a displacement reaction
US20030059604A1 (en) * 2001-09-05 2003-03-27 Fuji Photo Film Co., Ltd. Material coated with dispersion of ferromagnetic nanoparticles, and magnetic recording medium using the material
US6574130B2 (en) 2001-07-25 2003-06-03 Nantero, Inc. Hybrid circuit having nanotube electromechanical memory
US6582673B1 (en) 2000-03-17 2003-06-24 University Of Central Florida Carbon nanotube with a graphitic outer layer: process and application
US6643165B2 (en) 2001-07-25 2003-11-04 Nantero, Inc. Electromechanical memory having cell selection circuitry constructed with nanotube technology
US6706402B2 (en) 2001-07-25 2004-03-16 Nantero, Inc. Nanotube films and articles
US20040057893A1 (en) * 2000-01-11 2004-03-25 Toyo Tanso Co., Ltd. Carbon material for producing metal-including fullerene in high yield
US6741019B1 (en) * 1999-10-18 2004-05-25 Agere Systems, Inc. Article comprising aligned nanowires
US6740403B2 (en) 2001-04-02 2004-05-25 Toyo Tanso Co., Ltd. Graphitic polyhederal crystals in the form of nanotubes, whiskers and nanorods, methods for their production and uses thereof
US20040156784A1 (en) * 2001-03-08 2004-08-12 Markus Haase Paramagnetic nanoparticle
US6784028B2 (en) 2001-12-28 2004-08-31 Nantero, Inc. Methods of making electromechanical three-trace junction devices
US20040170868A1 (en) * 2003-02-28 2004-09-02 Fuji Photo Film Co., Ltd. Magnetic particle coated material containing magnetic particles having CuAu type or Cu3Au type ferromagnetic ordered alloy phase, and method for producing the same
US6835591B2 (en) 2001-07-25 2004-12-28 Nantero, Inc. Methods of nanotube films and articles
US6841509B1 (en) * 2003-07-21 2005-01-11 Industrial Technology Research Institute Carbon nanocapsule supported catalysts
US20050056119A1 (en) * 2002-08-02 2005-03-17 Industrial Technology Research Institute Preparation of magnetic metal-filled carbon nanocapsules
US20050116195A1 (en) * 2002-01-07 2005-06-02 Tsang Shik C. Microparticles and methods of making them
US6911682B2 (en) 2001-12-28 2005-06-28 Nantero, Inc. Electromechanical three-trace junction devices
US6919592B2 (en) 2001-07-25 2005-07-19 Nantero, Inc. Electromechanical memory array using nanotube ribbons and method for making same
US20050200438A1 (en) * 2002-02-25 2005-09-15 Philippe Renaud Magnetic nanomaterials and synthesis method
US20060029741A1 (en) * 2002-10-21 2006-02-09 Fuji Photo Film Co., Ltd. Magnetic particle-coated material, magnetic recording medium, electromagnetic shield material, and methods of manufacturing same
WO2006017333A2 (en) * 2004-07-13 2006-02-16 William Marsh Rice University Shortened carbon nanotubes
US20060040388A1 (en) * 2003-12-18 2006-02-23 Bromberg Lev E Bioprocesses enhanced by magnetic nanoparticles
US7063753B1 (en) 2003-07-01 2006-06-20 Yingjian Chen Electronic device utilizing magnetic nanotubes
DE102005005704A1 (en) * 2005-02-03 2006-08-10 Hamstein Consult Gmbh Particles for determining the local temperature in organic and non-organic bodies
US20060210636A1 (en) * 2002-12-09 2006-09-21 Ralph Nonninger Nanoscale core/shell particles and the production thereof
US7176505B2 (en) 2001-12-28 2007-02-13 Nantero, Inc. Electromechanical three-trace junction devices
US7274078B2 (en) 2001-07-25 2007-09-25 Nantero, Inc. Devices having vertically-disposed nanofabric articles and methods of making the same
US20070241747A1 (en) * 2005-10-07 2007-10-18 Morley Gavin W Multiple SQUID magnetometer
US7304357B2 (en) 2001-07-25 2007-12-04 Nantero, Inc. Devices having horizontally-disposed nanofabric articles and methods of making the same
US7335395B2 (en) 2002-04-23 2008-02-26 Nantero, Inc. Methods of using pre-formed nanotubes to make carbon nanotube films, layers, fabrics, ribbons, elements and articles
US7384680B2 (en) 1997-07-21 2008-06-10 Nanogram Corporation Nanoparticle-based power coatings and corresponding structures
CN100510171C (en) 2007-12-12 2009-07-08 四川大学 Preparation method of carbon coated TiO* core-shell composite nanometer powder
US7560136B2 (en) 2003-01-13 2009-07-14 Nantero, Inc. Methods of using thin metal layers to make carbon nanotube films, layers, fabrics, ribbons, elements and articles
US7566478B2 (en) 2001-07-25 2009-07-28 Nantero, Inc. Methods of making carbon nanotube films, layers, fabrics, ribbons, elements and articles
US20090233098A1 (en) * 1997-10-31 2009-09-17 Nanogram Corporation Cerium oxide nanoparticles
US20090317557A1 (en) * 2008-06-20 2009-12-24 Toyota Motor Engineering & Manufacturing North America, Inc. Process To Make Core-Shell Structured Nanoparticles
US20090317719A1 (en) * 2008-06-20 2009-12-24 Toyota Motor Engineering & Manufacturing North America, Inc. Material With Core-Shell Structure
US7750297B1 (en) 2007-03-09 2010-07-06 University Of Central Florida Research Foundation, Inc. Carbon nanotube collimator fabrication and application
US7847207B1 (en) 2000-03-17 2010-12-07 University Of Central Florida Research Foundation, Inc. Method and system to attach carbon nanotube probe to scanning probe microscopy tips
US7879308B1 (en) 2000-03-17 2011-02-01 University Of Central Florida Research Foundation, Inc. Multiwall carbon nanotube field emitter fabricated by focused ion beam technique
EP2383374A1 (en) 2010-04-29 2011-11-02 BASF Corporation Nano-particles containing carbon and a ferromagnetic metal or alloy
US20140264144A1 (en) * 2013-03-15 2014-09-18 Honda Motor Co., Ltd. Method for Preparation of Various Carbon Allotropes based Magnetic Adsorbents with High Magnetization
US9048486B2 (en) 2011-11-08 2015-06-02 Samsung Sdi Co., Ltd. Negative active material, method of preparing the negative active material, electrode including the negative active material, and lithium battery including the electrode
US9588191B1 (en) 2008-08-18 2017-03-07 Hypres, Inc. High linearity superconducting radio frequency magnetic field detector
US10410773B2 (en) 2013-09-12 2019-09-10 Toyota Motor Engineering & Manufacturing North America, Inc. Synthesis and annealing of manganese bismuth nanoparticles

Families Citing this family (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9418937D0 (en) * 1994-09-20 1994-11-09 Isis Innovation Opening and filling carbon nanotubes
US6048810A (en) * 1996-11-12 2000-04-11 Baychar; Waterproof/breathable moisture transfer liner for snowboard boots, alpine boots, hiking boots and the like
US8569190B2 (en) 1996-11-12 2013-10-29 Solid Water Holdings Waterproof/breathable moisture transfer liner for snowboard boots, alpine boots, hiking boots and the like
US20050034330A1 (en) * 1996-11-12 2005-02-17 Baychar Running shoes, hiking shoes and boots, snowboard boots, alpine boots, hiking boots, and the like, having waterproof/breathable moisture transfer characteristics
US20070281567A1 (en) * 2004-04-05 2007-12-06 Solid Water Holding Waterproof/breathable technical apparel
US20040200094A1 (en) * 1996-11-12 2004-10-14 Baychar Softboots and waterproof /breathable moisture transfer composite and liner for in-line skates, ice-skates, hockey skates, snowboard boots, alpine boots, hiking boots and the like
US20080131648A1 (en) * 2003-06-23 2008-06-05 Solid Water Holdings Waterproof/breathable, moisture transfer, soft shell alpine boots and snowboard boots, insert liners and footbeds
US5879715A (en) * 1997-09-02 1999-03-09 Ceramem Corporation Process and system for production of inorganic nanoparticles
US6387531B1 (en) 1998-07-27 2002-05-14 Nanogram Corporation Metal (silicon) oxide/carbon composite particles
US6506493B1 (en) 1998-11-09 2003-01-14 Nanogram Corporation Metal oxide particles
US20030185892A1 (en) * 2001-08-17 2003-10-02 Bell Steve J. D. Intraocular delivery compositions and methods
WO2000046147A2 (en) * 1999-02-03 2000-08-10 Biosante Pharmaceuticals, Inc. Therapeutic calcium phosphate particles and methods of manufacture and use
US20040258763A1 (en) * 1999-02-03 2004-12-23 Bell Steve J.D. Methods of manufacture and use of calcium phosphate particles containing allergens
US20020054914A1 (en) * 1999-02-03 2002-05-09 Tulin Morcol Compositions and methods for therapuetic agents complexed with calcium phosphate and encased by casein
US20020187889A1 (en) * 1999-10-28 2002-12-12 Lauf Robert J. Mixed oxide nanoparticles and apparatus for making same
JP2002121601A (en) * 2000-10-16 2002-04-26 Aisin Seiki Co Ltd Soft magnetic metal powder particle and treating method thereof, and soft magnetic compact and its manufacturing method
JP2004220670A (en) * 2003-01-14 2004-08-05 Hitachi Ltd Method for forming nanoparticle film aligned in axis of easy magnetization, magnetic recording medium using the same and manufacturing method and apparatus thereof
US7004993B2 (en) * 2003-06-13 2006-02-28 Philip Morris Usa Inc. Nanoscale particles of iron aluminide and iron aluminum carbide by the reduction of iron salts
WO2005084637A2 (en) * 2004-02-13 2005-09-15 Nod Pharmaceuticals, Inc. Particles comprising a core of calcium phosphate nanoparticles, a biomolecule and a bile acid, methods of manufacturing, therapeutic use thereof
US7405002B2 (en) * 2004-08-04 2008-07-29 Agency For Science, Technology And Research Coated water-soluble nanoparticles comprising semiconductor core and silica coating
US7534489B2 (en) * 2004-09-24 2009-05-19 Agency For Science, Technology And Research Coated composites of magnetic material and quantum dots
EP1811941A4 (en) * 2004-11-01 2008-09-10 Biosante Pharmaceuticals Inc Therapeutic calcium phosphate particles iin use for aesthetic or cosmetic medicine, and methods of manufacture and use
US7719265B2 (en) * 2004-11-17 2010-05-18 Honda Motor Co., Ltd. Methods for determining particle size of metal nanocatalyst for growing carbon nanotubes
US20070141940A1 (en) * 2005-10-28 2007-06-21 Lightweight, breathable, waterproof, soft shell composite apparel and technical alpine apparel
US20070294920A1 (en) * 2005-10-28 2007-12-27 Soft shell boots and waterproof /breathable moisture transfer composites and liner for in-line skates, ice-skates, hockey skates, snowboard boots, alpine boots, hiking boots and the like
US7803210B2 (en) * 2006-08-09 2010-09-28 Napra Co., Ltd. Method for producing spherical particles having nanometer size, crystalline structure, and good sphericity
DE102008014800B3 (en) * 2008-03-18 2009-08-20 Federal-Mogul Burscheid Gmbh Method and apparatus for producing a dispersion-hardened article containing carbide nanoparticles
US9330821B2 (en) 2008-12-19 2016-05-03 Boutiq Science Limited Magnetic nanoparticles
US8658056B1 (en) 2010-05-05 2014-02-25 The United States Of America As Represented By The Secretary Of The Air Force Harvesting single domain nanoparticles and their applications
RU2530070C1 (en) * 2013-04-23 2014-10-10 Федеральное государственное бюджетное учреждение науки Институт теплофизики им. С.С. Кутателадзе Сибирского отделения Российской академии наук (ИТ СО РАН) METHOD FOR SYNTHESIS OF HOLLOW NANOPARTICLES OF γ-Al2O3
US9409148B2 (en) 2013-08-08 2016-08-09 Uchicago Argonne, Llc Compositions and methods for direct capture of organic materials from process streams

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1357777A (en) * 1963-02-27 1964-04-10 Cabot Corp improved magnetic carbon black pigments and improved process for producing these pigments
US5176260A (en) * 1988-09-28 1993-01-05 Exportech Company, Inc. Method of magnetic separation and apparatus therefore
US5248498A (en) * 1991-08-19 1993-09-28 Mallinckrodt Medical, Inc. Fullerene compositions for magnetic resonance spectroscopy and imaging
US5304366A (en) * 1991-12-24 1994-04-19 Sri International Process and apparatus for producing and separating fullerenes

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3661567A (en) * 1967-12-06 1972-05-09 Matsushita Electric Ind Co Ltd Magnet alloys
AU472514B2 (en) * 1973-08-02 1976-05-27 Matsushita Electric Industrial Co., Ltd. ANISTROPIC PERMANENT MAGNET OF Mn-ALC ALLOY
JPS5061698A (en) * 1973-10-03 1975-05-27
US4043845A (en) * 1975-11-28 1977-08-23 Raytheon Company Carbon stabilized cobalt-rare earth magnetic materials
JPS5914532B2 (en) * 1976-08-27 1984-04-05 Matsushita Electric Ind Co Ltd
US4187170A (en) * 1977-01-27 1980-02-05 Foxboro/Trans-Sonics, Inc. Magnetic techniques for separating non-magnetic materials
US5127586A (en) * 1988-09-28 1992-07-07 Exprotech Company, Inc. Method of magnetic separation and apparatus therefore

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1357777A (en) * 1963-02-27 1964-04-10 Cabot Corp improved magnetic carbon black pigments and improved process for producing these pigments
US5176260A (en) * 1988-09-28 1993-01-05 Exportech Company, Inc. Method of magnetic separation and apparatus therefore
US5248498A (en) * 1991-08-19 1993-09-28 Mallinckrodt Medical, Inc. Fullerene compositions for magnetic resonance spectroscopy and imaging
US5304366A (en) * 1991-12-24 1994-04-19 Sri International Process and apparatus for producing and separating fullerenes

Non-Patent Citations (12)

* Cited by examiner, † Cited by third party
Title
B. Diggs et al., Journal of Applied Physics, vol. 75, No. 10, (May 1994). *
J. Svoboda, Magnetic Methods For The Treatments Of Minerals, pp. 3 4 (1987). *
J. Svoboda, Magnetic Methods For The Treatments Of Minerals, pp. 3-4 (1987).
M. E. McHenry et al., Physical Review, B. Condensed Matter, vol. 49, No. 16, pp. 11358 11363, (Apr. 1994). *
M. E. McHenry et al., Physical Review, B. Condensed Matter, vol. 49, No. 16, pp. 11358-11363, (Apr. 1994).
M. Tomita, Y. Saito and T. Hayashi, "LaC2 Encapsulated in Graphite Nano-Particle", Jpn. J. Appl. Phys., vol. 32, p. 280 (Feb. 1993).
M. Tomita, Y. Saito and T. Hayashi, LaC 2 Encapsulated in Graphite Nano Particle , Jpn. J. Appl. Phys., vol. 32, p. 280 (Feb. 1993). *
P. Byszewski et al. "Weak Ferromagnetism Of Fe Intercalated Fullerides, European Conference, Physics of Magnetism", ACTA Physica Polonica A, vol. 85, No. 2, pp. 298-299, Feb. 1994.
P. Byszewski et al. Weak Ferromagnetism Of Fe Intercalated Fullerides, European Conference, Physics of Magnetism , ACTA Physica Polonica A, vol. 85, No. 2, pp. 298 299, Feb. 1994. *
R. S. Rouff, D. C. Lorents, B. Chan, R. Malhotra and S. Subramoney, "Single Crystal Metals Encapsulated In Carbon Nanoparticles", Science, vol. 259, p. 346 (1993).
R. S. Rouff, D. C. Lorents, B. Chan, R. Malhotra and S. Subramoney, Single Crystal Metals Encapsulated In Carbon Nanoparticles , Science, vol. 259, p. 346 (1993). *
S. A. Majetich et al., Physical Review, B. Condensed Matter, vol. 8, No. 22, (Dec. 1993). *

Cited By (95)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5783263A (en) * 1993-06-30 1998-07-21 Carnegie Mellon University Process for forming nanoparticles
US5660397A (en) * 1994-09-23 1997-08-26 Holtkamp; William H. Devices employing a liquid-free medium
US5704613A (en) * 1994-09-23 1998-01-06 Holtkamp; William H. Methods for sealing and unsealing using a magnetically permeable solid-based medium
US6231980B1 (en) * 1995-02-14 2001-05-15 The Regents Of The University Of California BX CY NZ nanotubes and nanoparticles
US5984996A (en) * 1995-02-15 1999-11-16 The University Of Connecticut Nanostructured metals, metal carbides, and metal alloys
US6033624A (en) * 1995-02-15 2000-03-07 The University Of Conneticut Methods for the manufacturing of nanostructured metals, metal carbides, and metal alloys
US5627140A (en) * 1995-05-19 1997-05-06 Nec Research Institute, Inc. Enhanced flux pinning in superconductors by embedding carbon nanotubes with BSCCO materials
WO1997019208A1 (en) * 1995-11-22 1997-05-29 Northwestern University Method of encapsulating a material in a carbon nanotube
US5916642A (en) * 1995-11-22 1999-06-29 Northwestern University Method of encapsulating a material in a carbon nanotube
US5766306A (en) * 1996-06-04 1998-06-16 The Boeing Company Continuous process for making nanoscale amorphous magnetic metals
US5834057A (en) * 1996-06-28 1998-11-10 The United States Is Represented By The Secretary Of The Navy Method of making chemically engineered metastable alloys and multiple components nanoparticles
US7384680B2 (en) 1997-07-21 2008-06-10 Nanogram Corporation Nanoparticle-based power coatings and corresponding structures
US6340245B1 (en) * 1997-09-16 2002-01-22 Skf Engineering & Research Centre B.V. Coated rolling element bearing
US6290735B1 (en) * 1997-10-31 2001-09-18 Nanogram Corporation Abrasive particles for surface polishing
US20090233098A1 (en) * 1997-10-31 2009-09-17 Nanogram Corporation Cerium oxide nanoparticles
US7258706B2 (en) 1997-10-31 2007-08-21 Nanogram Corporation Abrasive particles for surface polishing
US8048523B2 (en) 1997-10-31 2011-11-01 Nanogram Corporation Cerium oxide nanoparticles
US6376063B1 (en) 1998-06-15 2002-04-23 The Boeing Company Making particulates of controlled dimensions by electroplating
US6699579B2 (en) 1998-06-15 2004-03-02 The Boeing Company Particulates of controlled dimension
US6741019B1 (en) * 1999-10-18 2004-05-25 Agere Systems, Inc. Article comprising aligned nanowires
US20040057893A1 (en) * 2000-01-11 2004-03-25 Toyo Tanso Co., Ltd. Carbon material for producing metal-including fullerene in high yield
US7078006B2 (en) * 2000-01-11 2006-07-18 Toyo Tanso Co., Ltd. Carbon material for producing metal-including fullerene in high yield
US7011884B1 (en) 2000-03-17 2006-03-14 University Of Central Florida Research Foundation, Inc. Carbon nanotube with a graphitic outer layer
US7847207B1 (en) 2000-03-17 2010-12-07 University Of Central Florida Research Foundation, Inc. Method and system to attach carbon nanotube probe to scanning probe microscopy tips
US7879308B1 (en) 2000-03-17 2011-02-01 University Of Central Florida Research Foundation, Inc. Multiwall carbon nanotube field emitter fabricated by focused ion beam technique
US6582673B1 (en) 2000-03-17 2003-06-24 University Of Central Florida Carbon nanotube with a graphitic outer layer: process and application
US6479028B1 (en) 2000-04-03 2002-11-12 The Regents Of The University Of California Rapid synthesis of carbon nanotubes and carbon encapsulated metal nanoparticles by a displacement reaction
DE10111321A1 (en) * 2000-09-08 2002-05-23 Nanosolutions Gmbh Production of inorganic nanoparticles that can be fluoresced comprising host material containing dopant comprises using organic solvent for liquid phase synthesis of particles
US8088358B2 (en) 2001-03-08 2012-01-03 Centrum Fur Angewandte Nanotechnologie (Can) Gmbh Paramagnetic nanoparticle
US20040156784A1 (en) * 2001-03-08 2004-08-12 Markus Haase Paramagnetic nanoparticle
US6740403B2 (en) 2001-04-02 2004-05-25 Toyo Tanso Co., Ltd. Graphitic polyhederal crystals in the form of nanotubes, whiskers and nanorods, methods for their production and uses thereof
US6919592B2 (en) 2001-07-25 2005-07-19 Nantero, Inc. Electromechanical memory array using nanotube ribbons and method for making same
US7745810B2 (en) 2001-07-25 2010-06-29 Nantero, Inc. Nanotube films and articles
US6643165B2 (en) 2001-07-25 2003-11-04 Nantero, Inc. Electromechanical memory having cell selection circuitry constructed with nanotube technology
US6574130B2 (en) 2001-07-25 2003-06-03 Nantero, Inc. Hybrid circuit having nanotube electromechanical memory
US7342818B2 (en) 2001-07-25 2008-03-11 Nantero, Inc. Hybrid circuit having nanotube electromechanical memory
US6706402B2 (en) 2001-07-25 2004-03-16 Nantero, Inc. Nanotube films and articles
US6942921B2 (en) 2001-07-25 2005-09-13 Nantero, Inc. Nanotube films and articles
US7335528B2 (en) 2001-07-25 2008-02-26 Nantero, Inc. Methods of nanotube films and articles
US7304357B2 (en) 2001-07-25 2007-12-04 Nantero, Inc. Devices having horizontally-disposed nanofabric articles and methods of making the same
US7298016B2 (en) 2001-07-25 2007-11-20 Nantero, Inc. Electromechanical memory array using nanotube ribbons and method for making same
US8101976B2 (en) 2001-07-25 2012-01-24 Nantero Inc. Device selection circuitry constructed with nanotube ribbon technology
US7264990B2 (en) 2001-07-25 2007-09-04 Nantero, Inc. Methods of nanotubes films and articles
US6835591B2 (en) 2001-07-25 2004-12-28 Nantero, Inc. Methods of nanotube films and articles
US6836424B2 (en) 2001-07-25 2004-12-28 Nantero, Inc. Hybrid circuit having nanotube electromechanical memory
US7120047B2 (en) 2001-07-25 2006-10-10 Segal Brent M Device selection circuitry constructed with nanotube technology
US7274078B2 (en) 2001-07-25 2007-09-25 Nantero, Inc. Devices having vertically-disposed nanofabric articles and methods of making the same
US7056758B2 (en) 2001-07-25 2006-06-06 Nantero, Inc. Electromechanical memory array using nanotube ribbons and method for making same
US7566478B2 (en) 2001-07-25 2009-07-28 Nantero, Inc. Methods of making carbon nanotube films, layers, fabrics, ribbons, elements and articles
US20030059604A1 (en) * 2001-09-05 2003-03-27 Fuji Photo Film Co., Ltd. Material coated with dispersion of ferromagnetic nanoparticles, and magnetic recording medium using the material
US20060194039A1 (en) * 2001-09-05 2006-08-31 Fuji Photo Film Co., Ltd. Ferromagnetic nanoparticles, material coated with dispersion of ferromagnetic nanoparticles, and magnetic recording medium using the material
US7384449B2 (en) 2001-09-05 2008-06-10 Fujifilm Corporation Ferromagnetic nanoparticles, material coated with dispersion of ferromagnetic nanoparticles, and magnetic recording medium using the material
US7521736B2 (en) 2001-12-28 2009-04-21 Nantero, Inc. Electromechanical three-trace junction devices
US6979590B2 (en) 2001-12-28 2005-12-27 Nantero, Inc. Methods of making electromechanical three-trace junction devices
US6911682B2 (en) 2001-12-28 2005-06-28 Nantero, Inc. Electromechanical three-trace junction devices
US7176505B2 (en) 2001-12-28 2007-02-13 Nantero, Inc. Electromechanical three-trace junction devices
US6784028B2 (en) 2001-12-28 2004-08-31 Nantero, Inc. Methods of making electromechanical three-trace junction devices
US7915066B2 (en) 2001-12-28 2011-03-29 Nantero, Inc. Methods of making electromechanical three-trace junction devices
US20050116195A1 (en) * 2002-01-07 2005-06-02 Tsang Shik C. Microparticles and methods of making them
US7429339B2 (en) * 2002-02-25 2008-09-30 Freescale Semiconductor, Inc. Magnetic nanomaterials and synthesis method
US20050200438A1 (en) * 2002-02-25 2005-09-15 Philippe Renaud Magnetic nanomaterials and synthesis method
US7335395B2 (en) 2002-04-23 2008-02-26 Nantero, Inc. Methods of using pre-formed nanotubes to make carbon nanotube films, layers, fabrics, ribbons, elements and articles
US20050056119A1 (en) * 2002-08-02 2005-03-17 Industrial Technology Research Institute Preparation of magnetic metal-filled carbon nanocapsules
US6872236B1 (en) * 2002-08-02 2005-03-29 Industrial Technology Research Institute Preparation of magnetic metal-filled carbon nanocapsules
US20060029741A1 (en) * 2002-10-21 2006-02-09 Fuji Photo Film Co., Ltd. Magnetic particle-coated material, magnetic recording medium, electromagnetic shield material, and methods of manufacturing same
US20060210636A1 (en) * 2002-12-09 2006-09-21 Ralph Nonninger Nanoscale core/shell particles and the production thereof
US7560136B2 (en) 2003-01-13 2009-07-14 Nantero, Inc. Methods of using thin metal layers to make carbon nanotube films, layers, fabrics, ribbons, elements and articles
US20050142352A1 (en) * 2003-02-28 2005-06-30 Fuji Photo Film Co., Ltd. Magnetic particle coated material containing magnetic particles having CuAu type or Cu3Au type ferromagnetic ordered alloy phase, and method for producing the same
US20040170868A1 (en) * 2003-02-28 2004-09-02 Fuji Photo Film Co., Ltd. Magnetic particle coated material containing magnetic particles having CuAu type or Cu3Au type ferromagnetic ordered alloy phase, and method for producing the same
US7037605B2 (en) 2003-02-28 2006-05-02 Fuji Photo Film Co., Ltd. Magnetic particle coated material containing magnetic particles having CuAu type or Cu3Au type ferromagnetic ordered alloy phase, and method for producing the same
US7063753B1 (en) 2003-07-01 2006-06-20 Yingjian Chen Electronic device utilizing magnetic nanotubes
US6841509B1 (en) * 2003-07-21 2005-01-11 Industrial Technology Research Institute Carbon nanocapsule supported catalysts
US20060040388A1 (en) * 2003-12-18 2006-02-23 Bromberg Lev E Bioprocesses enhanced by magnetic nanoparticles
US7208134B2 (en) 2003-12-18 2007-04-24 Massachusetts Institute Of Technology Bioprocesses enhanced by magnetic nanoparticles
US20060051290A1 (en) * 2004-07-13 2006-03-09 William Marsh Rice University Short carbon nanotubes as adsorption and retention agents
WO2006017333A3 (en) * 2004-07-13 2006-06-01 Univ Rice William M Shortened carbon nanotubes
US20080003182A1 (en) * 2004-07-13 2008-01-03 Wilson Lon J Shortened Carbon Nanotubes
WO2006017333A2 (en) * 2004-07-13 2006-02-16 William Marsh Rice University Shortened carbon nanotubes
DE102005005704A1 (en) * 2005-02-03 2006-08-10 Hamstein Consult Gmbh Particles for determining the local temperature in organic and non-organic bodies
DE102005005704B4 (en) * 2005-02-03 2010-08-12 Hamstein Consult Gmbh Use of particles for the determination of the local temperature in organic and non-organic bodies
US7863892B2 (en) * 2005-10-07 2011-01-04 Florida State University Research Foundation Multiple SQUID magnetometer
US20070241747A1 (en) * 2005-10-07 2007-10-18 Morley Gavin W Multiple SQUID magnetometer
US7750297B1 (en) 2007-03-09 2010-07-06 University Of Central Florida Research Foundation, Inc. Carbon nanotube collimator fabrication and application
CN100510171C (en) 2007-12-12 2009-07-08 四川大学 Preparation method of carbon coated TiO* core-shell composite nanometer powder
US20090317719A1 (en) * 2008-06-20 2009-12-24 Toyota Motor Engineering & Manufacturing North America, Inc. Material With Core-Shell Structure
US20090317557A1 (en) * 2008-06-20 2009-12-24 Toyota Motor Engineering & Manufacturing North America, Inc. Process To Make Core-Shell Structured Nanoparticles
US8623470B2 (en) 2008-06-20 2014-01-07 Toyota Motor Engineering & Manufacturing North America, Inc. Process to make core-shell structured nanoparticles
US9588191B1 (en) 2008-08-18 2017-03-07 Hypres, Inc. High linearity superconducting radio frequency magnetic field detector
US10333049B1 (en) 2008-08-18 2019-06-25 Hypres, Inc. High linearity superconducting radio frequency magnetic field detector
WO2011136654A1 (en) 2010-04-29 2011-11-03 Basf Corporation Nano-particles containing carbon and a ferromagnetic metal or alloy
EP2383374A1 (en) 2010-04-29 2011-11-02 BASF Corporation Nano-particles containing carbon and a ferromagnetic metal or alloy
US9048486B2 (en) 2011-11-08 2015-06-02 Samsung Sdi Co., Ltd. Negative active material, method of preparing the negative active material, electrode including the negative active material, and lithium battery including the electrode
US20140264144A1 (en) * 2013-03-15 2014-09-18 Honda Motor Co., Ltd. Method for Preparation of Various Carbon Allotropes based Magnetic Adsorbents with High Magnetization
US10166529B2 (en) * 2013-03-15 2019-01-01 Honda Motor Co., Ltd. Method for preparation of various carbon allotropes based magnetic adsorbents with high magnetization
US10410773B2 (en) 2013-09-12 2019-09-10 Toyota Motor Engineering & Manufacturing North America, Inc. Synthesis and annealing of manganese bismuth nanoparticles

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